Models & routing
IsonAI offers several model tiers with different capabilities and speeds. You can let IsonAI choose automatically (Adaptive) or lock a specific tier from the model picker in the chat top bar.
Terms used in these docs: tier/model is the engine that answers (Omni, LYT, PRME); mode is a behavior setting on top of it (Adaptive for tier selection, Thinking for reasoning depth).
Adaptive (default)
Adaptive automatically picks the most suitable tier for each question — fast for simple things, deeper for complex ones. Most users can just use Adaptive and never think about model choice.
Weighty or high-stakes topics — legal, financial, medical, tax, scam detection, in-depth comparisons, and coding — are automatically routed to a stronger tier.
IsonAI Omni
The main tier for complex tasks: layered analysis, long reasoning, thorough comparisons, structured writing, and agentic behavior such as search-read-conclude across sources. Omni is also the engine behind Naya and Deep Research.
IsonAI LYT
The lightweight tier that prioritizes speed — for casual conversation, greetings, and simple everyday questions. LYT does not use the daily quota, so it stays available when the smart-model quota runs out. Its capabilities are more limited: web search is more concise and there is no deep reasoning. On LYT, Thinking always behaves as Fast.
PRME
The coding-specialist tier — strong at writing and analyzing code, mathematics, and structured technical analysis. PRME is only active when selected explicitly; Adaptive never routes questions to PRME on its own. PRME is also the engine behind IsonForge.
Explicit selection
Your choice in the model picker is always respected. If you lock Omni, every question is answered by Omni; the same goes for LYT and PRME. The only exceptions occur when quota runs out or a tier is temporarily unavailable (see below), and the change is always visible — never a silent substitution.
Fallback and degradation
- Quota exhausted — when the daily smart-model quota runs out, answers automatically continue on LYT until the quota renews, with a notice in the interface. See Plans & quota.
- Tier outage — if the main tier is temporarily unavailable, IsonAI switches to another healthy tier when possible to keep the service running.
- PRME — as an explicit tier, PRME shows a clear error message when its engine is unavailable, rather than silently answering with another tier.
Choosing the right tier
| Need | Choice |
|---|---|
| Everyday use | Adaptive |
| Deep analysis, long documents, important decisions | Omni |
| Light chat as fast as possible, quota-friendly | LYT |
| Writing or dissecting code | PRME (or Adaptive, which routes coding to Omni) |
Related
- Thinking — reasoning depth on top of any tier.
- Plans & quota — daily quota per tier.
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